Virtual kidney donation

ABSTRACT

A system includes a dialyzer having a blood side and a dialysate side, a first extracorporeal circuit including one or more first fluid connectors structurally configured to connect the blood side of the dialyzer to the vascular system of a kidney patient, and a second extracorporeal circuit including one or more second fluid connectors structurally configured to connect the dialysate side of the dialyzer to the vascular system of a healthy animal. The present teachings may thus include a system where hemodialysis is performed using a healthy animal (e.g., a person with normal kidney function) to help remove harmful solutes from, and provide helpful solutes to, a kidney patient. In this manner, the healthy animal is “virtually donating” its kidney function to the kidney patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/869,526, filed on Jan. 12, 2018, the entire contents of which arehereby incorporated by reference herein.

FIELD

The present disclosure generally relates to virtual kidney donation. Inparticular, it relates to devices, systems, and methods for hemodialysiswith limited resources, such as environments and settings with little orintermittent fresh water and/or energy.

BACKGROUND

In a typical hemodialysis procedure, which is usually conducted in adialysis outpatient facility or hospital but can be performed at home, akidney patient's blood is pumped through a dialyzer, where excess water,toxins, or other harmful solutes are removed. Then the processed bloodis pumped back into the kidney patient's bloodstream. Specifically,solutes are diffused across the dialyzer's semipermeable membrane intodialysate, where the dialysate flows in the opposite direction to bloodflow in an extracorporeal circuit. Ultrafiltration is achieved bycontrolling the trans-membrane pressure, causing water to move acrossthe membrane along a pressure gradient that is created. The dialysate istypically a sterilized solution of mineral ions, where urea and otherwaste products, potassium, and phosphate diffuse into the dialysate. Thedialysate may also include sodium and chloride (similar to those ofnormal plasma to prevent loss of such solutes), sodium bicarbonate(added to correct blood acidity), and a small amount of glucose. Duringa typical hemodialysis procedure, which lasts approximately three tofour hours, as much as sixty liters or more of fresh water may be usedto generate the dialysate required for the session.

In this manner, in a typical hemodialysis procedure, a power source forthe pump(s) (e.g., electricity) and fresh water (e.g., for thedialysate) are necessary items without which, dialysis cannot beperformed. Thus, dialysis treatments may be unavailable in environmentswhere access to such resources is limited, e.g., regions with developingor unreliable infrastructure (e.g., third-world countries oreconomically-challenged areas), undeveloped regions, anddisaster-stricken areas (e.g., a developed region affected by a naturaldisaster, military conflict, or the like that has temporarily disabledits infrastructure). There thus remains a need to provide hemodialysiswith limited resources.

SUMMARY

In an aspect, a system includes a dialyzer having a blood side and adialysate side, a first extracorporeal circuit including one or morefirst fluid connectors for connecting the blood side of the dialyzer tothe vascular system of a kidney patient, a second extracorporeal circuitincluding one or more second fluid connectors for connecting thedialysate side of the dialyzer to the vascular system of a healthyanimal, a first pump in fluid communication with at least one of thefirst and second extracorporeal circuits, and a driver mechanicallycoupled to the first pump, where the driver is configured to drive thefirst pump using energy from an energy source.

Implementations may include one or more of the following features. Thehealthy animal may be a human. The healthy animal may be a non-human.The driver may include a mechanical crank, where the energy source is ananimal. The mechanical crank may be a hand crank, where the animal is ahuman. The driver may include a motor and a photovoltaic cell, where theenergy source is light. The driver may include a motor, where the energysource is a battery. The system may further include a second pump. Thefirst pump may be in fluid communication with the first extracorporealcircuit, and the second pump may be in fluid communication with thesecond extracorporeal circuit. The second pump may be mechanicallycoupled to the driver. One or more of the first pump, the second pump,and the driver may be configured to establish a predetermined pressuregradient between the first and second extracorporeal circuits. Thepredetermined pressure gradient may be provided at least in part by apredetermined gear ratio difference between the first pump and thesecond pump. The system may further include a selector switch having atleast a first setting and a second setting, the first settingestablishing a zero-pressure gradient between the first and secondextracorporeal circuits, and the second setting establishing a nonzeropressure gradient between first and second extracorporeal circuits. Thepredetermined pressure gradient may be selected to implementultrafiltration from the first extracorporeal circuit to the secondextracorporeal circuit. The system may further include a resistiveelement in fluid communication with one or more of the firstextracorporeal circuit and the second extracorporeal circuit, theresistive element configured to establish a predetermined pressuregradient between the first and second extracorporeal circuits. Thedialyzer may include one or more of a hollow-fiber dialyzer and a platedialyzer. At least one of the one or more first fluid connectors and theone or more second fluid connectors may be primed with ananti-coagulant.

In an aspect, a method for performing hemodialysis includes moving bloodof a kidney patient through a first extracorporeal circuit including afirst fluid connector that connects a blood side of a dialyzer to thevascular system of the kidney patient, and moving one or more solutesthrough the dialyzer to a second extracorporeal circuit including asecond fluid connector that connects a dialysate side of the dialyzer tothe vascular system of a healthy animal.

Implementations may include one or more of the following features. Themethod may further include establishing a nonzero pressure gradient fromthe first extracorporeal circuit to the second extracorporeal circuit.One or more solutes moved through the second extracorporeal circuit mayinclude uremic toxins and metabolic waste extracted from the blood ofthe kidney patient, where the one or more solutes are moved from thedialyzer to the vascular system of the healthy animal for removal viakidney function of the healthy animal. One or more solutes moved throughthe second extracorporeal circuit may include healthy solutes extractedfrom the vascular system of the healthy animal and moved to the dialyzerfor mixing with the blood of the kidney patient.

In an aspect, a method includes connecting a blood side of a dialyzer tothe vascular system of a kidney patient to form a first extracorporealcircuit, and connecting a dialysate side of the dialyzer to the vascularsystem of a healthy animal to form a second extracorporeal circuitincluding a second fluid connector.

Implementations may include one or more of the following features. Themethod may further include establishing a nonzero pressure gradient fromthe first extracorporeal circuit to the second extracorporeal circuit.The method may further include moving blood of a kidney patient throughthe first extracorporeal circuit, and moving one or more solutes throughthe dialyzer to the second extracorporeal circuit.

These and other features, aspects, and advantages of the presentteachings will become better understood with reference to the followingdescription, examples, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the devices,systems, and methods described herein will be apparent from thefollowing description of particular embodiments thereof, as illustratedin the accompanying drawings. The drawings are not necessarily to scale,emphasis instead being placed upon illustrating the principles of thedevices, systems, and methods described herein. In the drawings, likereference numerals generally identify corresponding elements.

FIG. 1 illustrates a system for hemodialysis with limited resources, inaccordance with a representative embodiment.

FIG. 2 is a flow chart of a method for performing hemodialysis, inaccordance with a representative embodiment.

FIG. 3 is a flow chart of a method for hemodialysis, in accordance witha representative embodiment.

DETAILED DESCRIPTION

The embodiments will now be described more fully hereinafter withreference to the accompanying figures, in which preferred embodimentsare shown. The foregoing may, however, be embodied in many differentforms and should not be construed as limited to the illustratedembodiments set forth herein. Rather, these illustrated embodiments areprovided so that this disclosure will convey the scope to those skilledin the art.

All documents mentioned herein are hereby incorporated by reference intheir entirety. References to items in the singular should be understoodto include items in the plural, and vice versa, unless explicitly statedotherwise or clear from the text. Grammatical conjunctions are intendedto express any and all disjunctive and conjunctive combinations ofconjoined clauses, sentences, words, and the like, unless otherwisestated or clear from the context. Thus, the term “or” should generallybe understood to mean “and/or” and so forth.

Recitation of ranges of values herein are not intended to be limiting,referring instead individually to any and all values falling within therange, unless otherwise indicated herein, and each separate value withinsuch a range is incorporated into the specification as if it wereindividually recited herein. The words “about,” “approximately” or thelike, when accompanying a numerical value, are to be construed asindicating a deviation as would be appreciated by one of ordinary skillin the art to operate satisfactorily for an intended purpose. Similarly,words of approximation such as “about,” “approximately,” or“substantially” when used in reference to physical characteristics,should be understood to contemplate a range of deviations that would beappreciated by one of ordinary skill in the art to operatesatisfactorily for a corresponding use, function, purpose, or the like.Ranges of values and/or numeric values are provided herein as examplesonly, and do not constitute a limitation on the scope of the describedembodiments. Where ranges of values are provided, they are also intendedto include each value within the range as if set forth individually,unless expressly stated to the contrary. The use of any and allexamples, or exemplary language (“e.g.,” “such as,” or the like)provided herein, is intended merely to better illuminate the embodimentsand does not pose a limitation on the scope of the embodiments. Nolanguage in the specification should be construed as indicating anyunclaimed element as essential to the practice of the embodiments.

In the following description, it is understood that terms such as“first,” “second,” “top,” “bottom,” “up,” “down,” and the like, arewords of convenience and are not to be construed as limiting termsunless specifically stated to the contrary.

In general, the devices, systems, and methods disclosed herein generallyrelate to hemodialysis. Specifically, the devices, systems, and methodsdisclosed herein may relate to performing hemodialysis with limitedresources such as environments and settings with limited or noavailability or access to fresh water (e.g., that can be used forcreating dialysate) or energy (e.g., electricity) to run pumps and otherdialysis equipment and components. For example, the present teachingsmay be used in undeveloped, underdeveloped, or disaster-stricken regionsfor providing hemodialysis to patients. Also, or instead, the presentteachings may otherwise be used by patients outside of a treatmentfacility, e.g., when at home or when traveling.

To this end, the present teachings may include a hemodialysis systemthat does not require access to grid power to run pumps and othercomponents of the system. Also, or instead, the present teachings mayinclude a system where hemodialysis is performed using a healthy animal(e.g., a person with normal kidney function) to help remove harmfulsolutes from, and provide helpful solutes to, a kidney patient. In thismanner, the dialysate that would be used in a traditional treatment maybe replaced by the blood of a healthy animal without a need for a freshwater source. The healthy animal's blood may receive uremic toxins,metabolic waste, and excess water from the kidney patient's blood, whichcan then be cleared from the healthy animal via its normal kidneyfunction. Thus, the healthy animal is “virtually donating” its kidneyfunction to the kidney patient for the duration of the treatment.

The present teachings may thus include a traditional dialysisconfiguration (e.g., using a conventional dialyzer connected to a kidneypatient in a conventional manner), however, the present teachings mayinclude using a healthy animal with adequate kidney function toeventually remove harmful solutes (e.g., uremic toxins, potassium,phosphate, and so on) and to eventually provide helpful solutes to thekidney patient (e.g., sodium bicarbonate, glucose, and so on). That is,the dialyzer may be connected to the healthy animal's vascular systemusing the dialysate ports of the dialyzer. In this manner, the typicalconvective/diffusive processes may occur across a membrane of thedialyzer—uremic toxins and other metabolic waste migrate across themembrane from the kidney patient to the healthy animal. Moreover,ultrafiltration can be accomplished in a conventional manner—byestablishing a pressure gradient between the two sides of the dialyzer.The uremic toxins, metabolic waste, and excess water may then be clearedfrom the healthy animal via its normal kidney function.

FIG. 1 illustrates a system for hemodialysis with limited resources, inaccordance with a representative embodiment. As described herein, thesystem 100 may be used to perform hemodialysis when there is limited (orzero) access to grid power or fresh water. In this manner, the system100 may be used as an emergency replacement to a standard hemodialysissystem. The system 100 may generally include a kidney patient 102, ahealthy animal 104, a dialyzer 110, a first extracorporeal circuit 120,a second extracorporeal circuit 130, one or more pumps (e.g., a firstpump 140 and a second pump 150 as shown in the figure), one or moredrivers 160 for driving the one or more pumps, and an energy source 170for supplying energy to the one or more drivers 160.

The kidney patient 102 may include a human that has kidney disease(e.g., acute or chronic kidney disease), or has experienced a form ofkidney failure, thus needing dialysis treatments. The healthy animal 104may preferably include a human. The healthy animal 104 may alternativelyinclude a non-human, e.g., a horse, a cow, a sheep, and so on. It willbe understood that, although the use of a human as the healthy animal104 may be preferred, a non-human animal may be preferable to foregoingdialysis treatments entirely. In particular, some blood borne pathogensthat are typically found only in animals (e.g., prions that can causebovine spongiform encephalopathy (BSE), commonly known as mad cowdisease) are only about 10-nm in diameter, which is small enough tocross a typical dialyzer membrane. The risk of exposure to these orother blood borne pathogens may be weighed against the risk of foregoingdialysis entirely, on a case by case basis.

The term “healthy” as used herein when describing the healthy animal 104shall mean that the animal has apparently normal kidney function, where“normal” will be understood to mean kidney function that does not needsupplementation or treatment via dialysis or the like. Thus, the term“healthy” when describing the healthy animal 104 shall generally includean animal that has greater than about 15 percent of their kidneyfunction and/or has a glomerular filtration rate (GFR) of greater thanabout 15.

In the context of the present teachings, the kidney patient 102 can bethought of as simply a first animal, and the healthy animal 104 can bethought of as simply a second animal. The first animal may be any animalwhere it is desirous to perform dialysis on that animal's blood andreturn the processed blood to the animal. The second animal may be anyanimal whose blood contains solutes that are desirous for transfer intothe blood of the first animal, and/or any animal that has a kidneyfunction such that solutes transferred from the blood of the firstanimal will not significantly harm the second animal (e.g., the solutesmay be cleared from the second animal via its normal kidney function,i.e., where dilution of the solutes will occur in the second animalwithout significant adverse effects). Thus, generally, the presentteachings may use two living animals that form parts of the firstextracorporeal circuit 120 and the second extracorporeal circuit 130 inthe system 100.

The dialyzer 110 may be any as known in the art, e.g., a standard“off-the-shelf” dialyzer. For example, the dialyzer 110 may include oneor more of a hollow-fiber dialyzer and a plate dialyzer. In general, thedialyzer 110 may include a semipermeable membrane for the diffusion ofone or more solutes therethrough.

As such, the dialyzer 110 may include a blood side 112 and a dialysateside 114. The term “dialysate side” is a term of convenience usedconsistently with standard terminology, and does not indicate anintended use. In particular, this document makes reference to a“dialysate side” of a dialyzer, even when blood of a healthy animal 104(and not dialysate) is flowing therethrough.

The first extracorporeal circuit 120 may include one or more first fluidlines and/or connectors 122 for connecting the blood side 112 of thedialyzer 110 to the vascular system of the kidney patient 102. Ingeneral, the first extracorporeal circuit 120 may provide a fluid pathfor drawing blood from the kidney patient 102 through the dialyzer 110and back into the vascular system of the kidney patient 102 therebyproviding processed blood to the kidney patient 102. Other than thesemi-permeable membrane within the dialyzer 110, the firstextracorporeal circuit 120 may be isolated from the secondextracorporeal circuit 130 in the system 100.

The first lines and/or fluid connectors 122 may include tubing such asintravenous (IV) tubing made from any suitable material, includingwithout limitation, one or more of polypropylene, nylon, dynaflex, andthe like. The first fluid lines and/or connectors 122, or generally thefirst extracorporeal circuit 120, may also or instead include devices orcomponents used to gain access to the blood of the kidney patient 102for hemodialysis, including without limitation, one or more of an IVcatheter, a synthetic graft, and the like.

The second extracorporeal circuit 130 may include one or more secondfluid connectors 132 for connecting the dialysate side 114 of thedialyzer 110 to the vascular system of a healthy animal 104. In general,the second extracorporeal circuit 130 may provide a fluid path fordrawing blood from the healthy animal 104 through the dialyzer 110 andback into the vascular system of the healthy animal 104. In this manner,the blood from the healthy animal 104 may act in the role of thedialysate during a traditional HD treatment using the hemodialysissystem 100. In other words, one or more solutes may be moved to or fromthe second extracorporeal circuit 130. These solutes may includeunwanted or harmful solutes—uremic toxins, metabolic waste, and excesswater extracted from the blood of the kidney patient, or beneficialsolutes extracted from the vascular system of the healthy animal 104.

The second fluid connectors 132 may be the same or similar to the firstfluid connectors 122. Similarly, the second fluid connectors 132, orgenerally the second extracorporeal circuit 130, may also or insteadinclude devices or components used to gain access to the blood of thehealthy animal 104, including without limitation, one or more of an IVcatheter, a synthetic graft, and the like. In some implementations, apreliminary procedure may be performed on the healthy animal 104 to makevascular access more convenient. Such procedures may include, e.g.,creating a venous-venous connection, an arterio-arterio connection, anarterio-venous connection including an arterio-venous fistula or graft,inserting an indwelling needle or cannula, a Venflon device or similar,a catheter, a Port-A-Cath device or similar, a peripherally insertedcentral catheter (PICC), and the like into one or more blood vessels.

In some implementations, the first and/or second fluid connectors 122,132 may be pre-primed with an anti-coagulant such as heparin. Thisadvantageously reduces the deployment time of the system 100.

As discussed above, the system 100 may include one or more pumps, e.g.,a first pump 140 in fluid communication with the first extracorporealcircuit 120 and a second pump 150 in fluid communication with the secondextracorporeal circuit 130. In other aspects, the system 100 may includea single pump that is connected to each of the first extracorporealcircuit 120 and the second extracorporeal circuit 130. For example, thesystem 100 may include a first pump 140 in fluid communication with atleast one of the first extracorporeal circuit 120 and the secondextracorporeal circuit 130. Whether using a single pump (e.g., the firstpump 140), or a plurality of pumps (e.g., the first pump 140 and thesecond pump 150), the pump(s) may be operable to provide independent,but coordinated, control over the fluid flow in each of the firstextracorporeal circuit 120 and the second extracorporeal circuit 130.

One or more of the pumps, e.g., the first pump 140 and the second pump150, may be connected to one or more drivers 160 for driving the pumps.For example, each pump may be operably (e.g., mechanically) coupled tothe same driver 160. In this manner, the first pump 140 and the secondpump 150 may be mechanically coupled to the driver 160 as shown in thefigure. Alternatively, different pumps in the system 100 may beconnected to different drivers 160, but this can complicate the system100 for establishing a predetermined pressure gradient between the firstextracorporeal circuit 120 and the second extracorporeal circuit 130 asdiscussed herein. Thus, it may be preferable that each pump ismechanically coupled to the same driver 160 in the system 100.

So that ultrafiltration can be performed, one or more of the first pump140, the second pump 150, and the driver 160 may be configured toestablish a predetermined pressure gradient between the firstextracorporeal circuit 120 and the second extracorporeal circuit 130.Stated otherwise, the predetermined pressure gradient may be selected toimplement ultrafiltration from the first extracorporeal circuit 120 tothe second extracorporeal circuit 130.

The predetermined pressure gradient may be provided at least in part bya predetermined gear ratio difference between the first pump 140 and thesecond pump 150. Further, a gear ratio difference between the first pump140 and the second pump 150 may be controllable in the system 100. Forexample, one or more of the first pump 140 and the second pump 150 mayinclude a plurality of gears 142, where different combinations or setsof gears 142 can be selectively used or configured for pumping fluid inthe extracorporeal circuits to achieve a predetermined gear ratio andthereby establish a predetermined pressure gradient between theextracorporeal circuits.

To this end, the system 100 may further include one or more selectorswitches 180. In certain aspects, a selector switch 180 has at least afirst setting and a second setting, where the first setting establishesa zero-pressure gradient between the first extracorporeal circuit 120and the second extracorporeal circuit 130, and where the second settingestablishes a nonzero pressure gradient between the first extracorporealcircuit 120 and the second extracorporeal circuit 130. Other settingsfor different nonzero pressure gradients are also possible using aselector switch 180.

By way of example, the selector switch 180 may be operable to switchbetween different sets of gears 142 in one or more of the pumps. This isshown by way of representation in the figure, where the first pump 140includes a first set of gears 144 and a second set of gears 146. Theselector switch 180 may be operable to toggle between the first set ofgears 144 and a second set of gears 146. In this manner, the selectorswitch 180 may include a mechanical toggle, a wheel, a slider, a valve,or another similar mechanical input device that switches between sets ofgears 142 (or otherwise redirects or adjusts flow) to control a pressuregradient between the first extracorporeal circuit 120 and the secondextracorporeal circuit 130 in the system 100. The selector switch 180,or other components in the system 100, may alternatively beelectronically operated or controlled.

In implementations, the range of available pressure gradients may fallbetween those affording a standard clinical range of ultrafiltrationrates. For example, pressure gradients resulting in an ultrafiltrationrate from 0 L/hour to 1 L/hour may be implemented.

The pumps in the system 100 may include any as known in the art ofhemodialysis. For example, one or more of the pumps may include, withoutlimitation, a peristaltic pump (e.g., a roller pump), a syringe pump, acentrifugal pump, and so on. More generally, any pump capable of pumpingblood may be used in the system 100. In an aspect, each of the firstpump 140 and the second pump 150 include a peristaltic pump; in thismanner, it will be understood that the gears 142 described herein andshown in the figure may include rollers or the like instead of “gears”in the traditional sense (e.g., the gears 142 may lack teeth/cogs).

One or more drivers 160 may be used to drive the pumps in the system100. For example, the driver 160 may be mechanically coupled to thefirst pump 140, where the driver 160 is configured to drive the firstpump 140 using energy from the energy source 170. The driver 160 maysimilarly be mechanically coupled to the second pump 150, where thedriver 160 is configured to drive the second pump 150 using energy fromthe energy source 170. Thus, the energy source 170 may supply energy toone or more drivers 160 in the system 100.

In implementations, the driver 160 may include a mechanical crank 162,where the energy source 170 is an animal. For example, the mechanicalcrank 162 may include a hand or foot crank, where the animal is a humanthat uses the hand or foot crank to create energy for activating thedriver 160 to drive the pump(s). In implementations, the driver 160 mayinclude a motor and a photovoltaic cell, where the energy source islight, e.g., sunlight. In some implementations, the driver 160 includesa motor, where the energy source is a battery or the like. The driver160, energy source 170, or both, may also or instead be integral withone or more of the pumps or another component of the system 100.

Thus, as described herein, the system 100 may be operable without theuse of grid power, such that the system 100 could be utilized forhemodialysis when disposed in an area lacking relatively easy access toelectricity. Also, because the blood of the healthy animal 104 may beused as the dialysate in the system 100, the system 100 could beutilized for hemodialysis when disposed in an area lacking relativelyeasy access to fresh water.

The system 100 may further include one or more other hemodialysiscomponents 190. The other hemodialysis components 190 may be disposed onone or more of the first extracorporeal circuit 120 and the secondextracorporeal circuit 130, or otherwise disposed in the system 100. Theother hemodialysis components 190 may include, without limitation, oneor more of a sensor, a pressure monitor (e.g., an arterial pressuremonitor, a venous pressure monitor, and the like), an air trap, an airdetector, a connector, a valve, a heparin pump, a saline drip (or otherdrip, or pharmaceutical solution), a reservoir, a heater, a controller,a resistive element, a reducer, and the like. For example, in an aspect,the pressure differential for ultrafiltration may be established byadding resistance (through the use of a hemodialysis component 190including a resistive element) to the first extracorporeal circuit 120(e.g., on a blood outlet on the blood side 112 of the dialyzer 110).This may be accomplished, e.g., by partially closing a valve on thefirst extracorporeal circuit 120. Thus, the hemodialysis component 190may include a resistive element such as a valve.

Thus, example advantages of the system 100 may include that it can beused without a source of fresh water (or traditional dialysate), andthat it can be used without grid power or another external energysource. However, it will be understood that the system 100 may also besupplemented with traditional components in the event that either freshwater (or traditional dialysate) or an external energy source isavailable. For example, in lieu of mechanically operated drives 160, thesystem 100 may include electrically-operated drives 160 for the pumps(i.e., the pump(s) may be electrically operated in an embodiment).

FIG. 2 is a flow chart of a method for performing hemodialysis, inaccordance with a representative embodiment. The method 200 may includethe use of a system such as that described in FIG. 1 above, e.g., ahemodialysis system that does not require access to grid power to runthe pumps and other components of the system.

As shown in step 202, the method 200 may include establishing a nonzeropressure gradient from a first extracorporeal circuit to a secondextracorporeal circuit. The first extracorporeal circuit may include afirst fluid connector that connects a blood side of a dialyzer to thevascular system of a kidney patient, and the second extracorporealcircuit may include a second fluid connector that connects a dialysateside of the dialyzer to the vascular system of a healthy animal.

As shown in step 204, the method 200 may include moving blood of akidney patient through the first extracorporeal circuit, and as shown instep 206, the method 200 may include moving one or more solutes throughthe dialyzer to the second extracorporeal circuit. The solutes movedthrough the second extracorporeal circuit may include one or more ofuremic toxins, metabolic waste, and excess water extracted from theblood of the kidney patient, where these solutes are moved from thedialyzer to the vascular system of the healthy animal for removal viakidney function of the healthy animal. The solutes moved through thesecond extracorporeal circuit may also or instead include healthysolutes extracted from the vascular system of the healthy animal andmoved to the dialyzer for mixing with the blood of the kidney patient.

FIG. 3 is a flow chart of a method for hemodialysis, in accordance witha representative embodiment. Similar to the method described above withreference to FIG. 2, the method 300 of FIG. 3 may include the use orsetup of a system such as that described in FIG. 1 above, e.g., ahemodialysis system that does not require access to grid power to runthe pumps and other components of the system.

As shown in step 302, the method 300 may include connecting a blood sideof a dialyzer to the vascular system of a kidney patient to form a firstextracorporeal circuit.

As shown in step 304, the method 300 may include connecting a dialysateside of the dialyzer to the vascular system of a healthy animal to forma second extracorporeal circuit.

As shown in step 306, the method 300 may include establishing a nonzeropressure gradient from the first extracorporeal circuit to the secondextracorporeal circuit.

As shown in step 308, the method 300 may include moving blood of akidney patient through the first extracorporeal circuit.

As shown in step 310, the method 300 may include moving one or moresolutes through the dialyzer to the second extracorporeal circuit.

The foregoing description, for purpose of explanation, has beendescribed with reference to specific embodiments. However, theillustrative discussions above are not intended to be exhaustive or tolimit the disclosure to the precise forms disclosed. Many modificationsand variations are possible in view of the above teachings.

Unless the context clearly requires otherwise, throughout thedescription, the words “comprise,” “comprising,” “include,” “including,”and the like are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Additionally, the words “herein,” “hereunder,”“above,” “below,” and words of similar import refer to this applicationas a whole and not to any particular portions of this application.

It will be appreciated that the devices, systems, and methods describedabove are set forth by way of example and not of limitation. Absent anexplicit indication to the contrary, the disclosed steps may bemodified, supplemented, omitted, and/or re-ordered without departingfrom the scope of this disclosure. Numerous variations, additions,omissions, and other modifications will be apparent to one of ordinaryskill in the art. In addition, the order or presentation of method stepsin the description and drawings above is not intended to require thisorder of performing the recited steps unless a particular order isexpressly required or otherwise clear from the context.

The method steps of the implementations described herein are intended toinclude any suitable method of causing such method steps to beperformed, consistent with the patentability of the following claims,unless a different meaning is expressly provided or otherwise clear fromthe context. So, for example performing the step of X includes anysuitable method for causing another party such as a remote user, aremote processing resource (e.g., a server or cloud computer) or amachine to perform the step of X. Similarly, performing steps X, Y and Zmay include any method of directing or controlling any combination ofsuch other individuals or resources to perform steps X, Y and Z toobtain the benefit of such steps. Thus, method steps of theimplementations described herein are intended to include any suitablemethod of causing one or more other parties or entities to perform thesteps, consistent with the patentability of the following claims, unlessa different meaning is expressly provided or otherwise clear from thecontext. Such parties or entities need not be under the direction orcontrol of any other party or entity, and need not be located within aparticular jurisdiction.

It should further be appreciated that the methods above are provided byway of example. Absent an explicit indication to the contrary, thedisclosed steps may be modified, supplemented, omitted, and/orre-ordered without departing from the scope of this disclosure.

It will be appreciated that the methods and systems described above areset forth by way of example and not of limitation. Numerous variations,additions, omissions, and other modifications will be apparent to one ofordinary skill in the art. In addition, the order or presentation ofmethod steps in the description and drawings above is not intended torequire this order of performing the recited steps unless a particularorder is expressly required or otherwise clear from the context. Thus,while particular embodiments have been shown and described, it will beapparent to those skilled in the art that various changes andmodifications in form and details may be made therein without departingfrom the spirit and scope of this disclosure and are intended to form apart of the invention as defined by the following claims, which are tobe interpreted in the broadest sense allowable by law.

What is claimed is:
 1. A system comprising: a dialyzer having a bloodside and a dialysate side; a first extracorporeal circuit including oneor more first fluid connectors structurally configured to connect theblood side of the dialyzer to the vascular system of a kidney patient;and a second extracorporeal circuit including one or more second fluidconnectors structurally configured to connect the dialysate side of thedialyzer to the vascular system of a healthy animal.
 2. The system ofclaim 1, wherein the healthy animal is a human.
 3. The system of claim1, wherein the healthy animal is a non-human.
 4. The system of claim 1,further comprising: a first pump in fluid communication with at leastone of the first and second extracorporeal circuits; and a drivermechanically coupled to the first pump, the driver configured to drivethe first pump using energy from an energy source.
 5. The system ofclaim 4, wherein the driver includes a mechanical crank, and wherein theenergy source is an animal.
 6. The system of claim 4, wherein the driverincludes a motor and a photovoltaic cell, and wherein the energy sourceis light.
 7. The system of claim 4, wherein the driver includes a motor,and wherein the energy source is a battery.
 8. The system of claim 4,further comprising a second pump.
 9. The system of claim 8, wherein thefirst pump is in fluid communication with the first extracorporealcircuit and the second pump is in fluid communication with the secondextracorporeal circuit.
 10. The system of claim 8, wherein the secondpump is mechanically coupled to the driver.
 11. The system of claim 8,wherein one or more of the first pump, the second pump, and the driverare configured to establish a predetermined pressure gradient betweenthe first and second extracorporeal circuits.
 12. The system of claim11, wherein the predetermined pressure gradient is provided at least inpart by a predetermined gear ratio difference between the first pump andthe second pump.
 13. The system of claim 11, further comprising aselector switch having at least a first setting and a second setting,the first setting establishing a zero-pressure gradient between thefirst and second extracorporeal circuits, and the second settingestablishing a nonzero pressure gradient between the first and secondextracorporeal circuits.
 14. The system of claim 11, wherein thepredetermined pressure gradient is selected to implement ultrafiltrationfrom the first extracorporeal circuit to the second extracorporealcircuit.
 15. The system of claim 1, wherein there is a nonzero pressuregradient between the first extracorporeal circuit and the secondextracorporeal circuit.
 16. The system of claim 15, further comprising aresistive element in fluid communication with one or more of the firstextracorporeal circuit and the second extracorporeal circuit, theresistive element configured to establish the nonzero pressure gradient.17. The system of claim 1, wherein the dialyzer includes a hollow-fiberdialyzer.
 18. The system of claim 1, wherein the dialyzer includes aplate dialyzer.
 19. The system of claim 1, wherein at least one of theone or more first fluid connectors and the one or more second fluidconnectors are primed with an anti-coagulant.
 20. The system of claim19, wherein the anti-coagulant includes heparin.